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The work of 146 kJ is performed in order to compress one kilo mole of gas adiabatically and in this process the temperature of the gas increases by 7°C. The gas is (R = 8.3 J mol⁻¹ K⁻¹)

1. diatomic
2. triatomic
3. a mixture of monoatomic and diatomic
4. monoatomic

Correct answer: diatomic

Solution

For adiabatic compression W = n*Cv*dT -> Cv = 146000/(1000*7) = 20.86 J/mol/K = 2.51R ~ (5/2)R, so the gas is diatomic.

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